BE/CNH: Coupling Human and Natural Influences on Coastline Evolution as Climate Changes

随着碎浪将沙子从一个地方移动到另一个地方，美国东南部和墨西哥湾海岸等沙质海岸线不断发生变化和重塑。 对这些海岸线如何在公里至数百公里的空间尺度以及数十年甚至更长时间的时间尺度上演化的研究才刚刚开始。 最近的研究揭示了令人惊讶的远程相互作用，一个位置的变化直接影响海岸线的遥远部分。 人类稳定海岸线位置的努力——特别是通过人工沙子放置或“海滩营养”——正变得越来越普遍，这些局部操作可能会通过其长期和区域影响影响整个海岸线的演变。 该研究项目将把人类的操作纳入一个增强的计算机模型中，该模型涉及由波浪驱动的沉积物输送引起的大规模、长期的海岸线变化。 解决完全耦合的人与自然系统的行为需要开发一个模型来代表人类如何应对海岸线变化，特别是当地海岸线侵蚀。 这样的模型将基于 (1) 包含历史海滩营养决策和经济变量的数据； (2) 经济理论；(3) 在沿海管理者、工程师、政策制定者和利益相关者参与的研讨会上收集的信息； (4)联邦海滩营养补贴的情景、购买海滩优质沙子的未来费用以及出于生态考虑而产生的政策限制。 由此产生的耦合模型将允许在可能的气候变化以及随之而来的风暴和波浪模式变化以及海平面加速上升的背景下，对未来几十年和几个世纪预期的海岸线行为类型进行调查。 卡罗莱纳州的海岸线将被用作测试该模型的初始案例研究。开发建模工作的社会科学部分将涉及对如何制定海滩营养决策的首次检查。 使用人类与海岸线耦合模型的实验将首次检验受人类影响的海岸线如何演变，更具体地说，在一个地点采取的行动可能如何影响遥远地区和附近的其他沿海社区。 通过这项工作获得的潜在见解可以帮助沿海管理者和规划者避免此类溢出效应带来的意外，随着气候变化和人类直接操纵成为影响海岸线变化的更重要因素，这一点尤其重要。 专门的网站和有针对性的沟通将有助于向感兴趣的沿海规划者和利益相关者传播主要经验教训。 更广泛地说，这项研究将推进人类与景观相互作用的胚胎科学，这种相互作用在地球表面的大部分地区变得无处不在。 该项目得到了 2005 财年环境生物复杂性特别竞赛的奖项的支持，该竞赛重点关注自然和人类系统耦合的动力学。

Sandy coastlines such as the U.S. Southeast and Gulf coasts are constantly shifted and reshaped as breaking waves move sand from one location to another. Research into how such coastlines evolve over spatial scales of kilometers to hundreds of kilometers and over time scales of decades and longer has just begun. Recent work has revealed surprising long-range interactions, with changes in one location directly affecting distant parts of the coastline. Human efforts to stabilize the shoreline position -- especially through artificial sand placement or "beach nourishment" -- are becoming increasingly prevalent, and these localized manipulations likely affect how entire coastlines evolve through their long-range as well as regional effects. This research project will incorporate human manipulations into an enhanced computer model of large-scale, long-term coastline change caused by wave-driven sediment transport. Addressing the behaviors of the fully coupled human-natural system will require developing a model that represents how humans respond to coastline changes, especially local shoreline erosion. Such a model will be based on (1) data that incorporates historical beach-nourishment decisions and economic variables; (2) economic theory;( 3) information gathered during a workshop involving coastal managers, engineers, policy makers, and stakeholders; and (4) scenarios of federal beach-nourishment subsidies, future expense of procuring beach-quality sand, and policy constraints arising from ecological concerns. The resulting coupled model will allow investigations of the types of coastline behaviors to be expected in coming decades and centuries in the context of likely climate change and the consequent changes in storm and wave patterns as well as accelerated sea-level-rise. The coastline of the Carolinas will be used as an initial case study to test the model.Developing the social science component of the modeling endeavor will involve the first examination of how beach nourishment decisions are made. Experiments using the coupled human-coastline model will provide the first examination of how human-influenced coastlines evolve, and more specifically, how actions taken at one location are likely to affect other coastal communities in far-flung locations as well as nearby. The potential insights gained through this work could help coastal managers and planners avoid surprises arising from such spillover effects, which could be especially important as climate change and direct human manipulations become more important factors affecting coastline change. A dedicated website and targeted communications will facilitate dissemination of the main lessons to interested coastal planners and stakeholders. More broadly, this research will advance the embryonic science of human-landscape interactions, which are becoming ubiquitous across much of the Earth's surface. This project is supported by an award resulting from the FY 2005 special competition in Biocomplexity in the Environment focusing on the Dynamics of Coupled Natural and Human Systems.